1. Field of the Invention
The present invention relates to apparatus for mixing two or more gas streams and distributing the gas mixture to the input of a reactor, for example, mixing a gaseous hydrocarbon feedstock with oxygen or an oxygen-containing gas and feeding the mixture to a catalytic reactor for partial oxidation of the feedstock.
2. Description of the Prior Art
Substantially complete mixing of gaseous reactants is highly desirable in a number of reactions, such as in partial catalytic oxidation. Uniform distribution of the mixed gases across the entrance of the reactor also provides for efficiency in the utilization of the reactor and uniformity in product. In U.S. Pat. application Ser. No. 07/085,159, filed Aug. 14, 1987, now U.S. Pat. No. 4,865,820, there is disclosed a gas mixer and distributor having an array of parallel tubes which receive first and second gases for mixing and distribution to the entrance of a catalytic reactor. A first chamber is connected to first ends of the tubes for distributing the first gas to the tubes. The tubes pass through a second chamber which distributes the second gas through openings in the walls of the tubes. The second ends of the tubes are gradually enlarged to distribute the gas mixture over the catalytic reactor entrance while preventing formation of vortices.
The above gas mixer and distributor of U.S. Pat. No. 4,865,820 has been found to enable the economical production of synthesis gas by catalytic partial oxidation of gaseous hydrocarbons in the absence of significant steam reforming reactions. However when gases of substantially different temperatures are fed to a mixer and distributor with a large number of tubes, the ratio of the gases in the mixture varies across the cross section of the reactor entrance. This reduces the efficiency of the reactor.